It was a "big moment," campaign manager Jim Messina said, because it was one of the states the Republicans had to get back into their column in order to get the 270 electoral votes needed for election.

The Bain attacks: Team Romney was aware that attacks on Romney's tenure at Bain Capital had been used in Romney's previous runs for office in 1994 and 2002, so the campaign in the fall of 2011 set up a task force headed by Bob White, one of his closest friends and also a former Bain executive, to be ready to answer any charges.

When the pro-Newt Gingrich super PAC went up with Bain attacks in January during the Republican primaries, Rhoades said, the team had rebuttal information ready within 24 to 48 hours. While Rhoades said aides thought the attacks could come during the primaries, "we were surprised a little by the intensity."

Mr. Preparation: Beth Myers, who directed Romney's debate preparation, said she wanted getting ready to debate the president to be the "Manhattan Project" of the campaign. The first general election debate prep came in June with policy sessions because officials knew this would be a good chance to give the campaign a jolt.

There were policy and strategy sessions in June, July and August. Myers made sure Romney was armed with a research book for any cross-country trip. During the Democratic convention in early September, Romney went to debate camp doing five mock debates in three days. And for "fun at night" the aides would do whiteboard review sessions.

Romney did 16 mock debates in total because those close to him knew that one way to help him relax was to make sure he was as prepared as possible.